TAS didn't note an issue with the SE input;
"Is there anything the Liquid Gold can’t do or are there any drawbacks we need to know about? I can think of two. First, note that the Liquid Gold is designed to power dynamic-type headphones, but not electrostatic ’phones. Those who have fallen in love with Stax’s superb SR-009 electrostatic headphones will need a dedicated electrostatic headphone amp (Cavalli’s Liquid Lightning MkII is ideal for such applications).
Second, the Liquid Gold absolutely will not and does not add any sort of sonic warmth or perceived “richness” to the music, unless, of course, those qualities are faithfully captured in your recordings. I mention this point because, frankly, a number of other fine headphone amplifiers do add a certain “tincture of warmth” to the musical proceedings, which is a euphonic coloration that I suspect some listeners will find appealing. If you want an amp that will generate its own aura of warmth or perceived richness, then the honest-to-a-fault Liquid Gold is probably not for you because it imparts very little sonic personality of its own. With recordings that sound vibrant, colorful, and alive the Gold will reflect precisely those qualities, but if fed thin, brittle-sounding, over-produced recordings, the Gold will unflinchingly reveal those characteristics, too—whether for good or ill. For my part, though, I find the transparency and honesty of the Cavalli refreshing and very desirable."